I know im abit late replying on here but i looked for this question just so that i could let everybody know before they start geting excited that the bleach had foamed when in contact with their urine and think that they are pregnant...sure they might be but dont rely on this bleach test myth, i was curiouse and it seemed abit off to me so i tested it the results i found ensured me that it is deffinetly not true, i expected i may be pregnant which i was be do happy about if i were so i tested with bleach and the result= it foamedI didnt get excited and politely begged my partner the pee in a plastic cup so i could test agin with his...the result=it foamed And then later on in the day i was cleaing my litter of kittens litter tray and realised tgey had missed the tray a little and peed on the wooden floor next to it so i put bleach onto it to kill the smell and clean it that also instantly foamed. So just just wanted to let people know so they dont rely on this test to be dissapointed if they later take a over the counter test and get a negative result.